AGU Fall Meeting 2023
Published:
I will be delivering a talk at the AGU Fall Meeting 2023 for the New Mars Underground III oral session. I will be presenting on recent work to determine strategic sampling times for the Curiosity rover to collect atmospheric methane samples in order to constrain diurnal and seasonal methane fluctuations.
https://agu.confex.com/agu/fm23/meetingapp.cgi/Paper/1320513
When: Thursday December 14th 2023 | 17:20 - 17:30 (PST)
Where: 216 - South (Level 2, South, Moscone Center)
Title: Sub-Diurnal Methane Variations on Mars Driven by Barometric Pumping and Planetary Boundary Layer Evolution
At @theAGU and interested in Mars? Come see my talk today in The New Mars Underground session aimed at identifying strategic times for @MarsCuriosity to collect atmospheric samples! #AGU2023 pic.twitter.com/ddeb1ofAyW
— John P. Ortiz (@JohnPOrtiz14) December 14, 2023
Abstract:
In recent years, the Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory (MSL) Curiosity rover has detected methane variations in the atmosphere at Gale crater. Methane concentrations appear to fluctuate seasonally as well as sub-diurnally, which is difficult to reconcile with an as-yet-unknown transport mechanism delivering the gas from underground to the atmosphere. We consider barometrically-induced transport of methane from an underground source to the surface, modulated by temperature-dependent adsorption as a mechanism to potentially explain the fluctuations. The subsurface fractured-rock seepage model is coupled to a simplified atmospheric mixing model to provide insights on the pattern of atmospheric methane concentrations in response to transient surface methane emissions, as well as to predict sub-diurnal variation in methane abundance for the Northern Summer period, which is a candidate time frame for Curiosity’s potentially final sampling campaign. The best-performing scenarios indicate a significant, short-lived methane pulse just prior to sunrise, the detection of which by SAM-TLS would be a potential indicator of the contribution of barometric pumping to Mars’ atmospheric methane variations.
